This invention relates to fluid pressure operated actuators and to a method of manufacture thereof. Fluid actuators are also identified in the art by various other terms such as linear motor, hydraulic or pneumatic cylinders or as fluid jacks.
A fluid actuator consists essentially of a cylinder member or barrel with closure means at each end and a slideable piston in the cylinder member coupled to a rod which extends axially through one end closure for connection to some mechanism which is to be shifted or controlled by the actuator. Fluid actuators are used in diverse variety of equipment to provide for a reciprocating motion of some element or for effecting pivoting movement of one element relative to another.
As heretofore constructed, fluid actuators have required a sizeable number of separable parts several of which have required costly machining to precise tolerances during manufacture. Joining of certain component parts has been provided for largely by threaded fastenings of some kind. Internal seals and bearings are usually required in a fluid actuator and these often deteriorate after a period of use. As it has been considered necessary to replace such seals and bearings from time to time, the construction of prior fluid actuators has been further complicated by provisions intended to facilitate disassembly and servicing in the field. As a consequence of these several factors, prior fluid actuators in general are costly and complex mechanisms requiring considerable care and maintenance and occasional repairs.